package com.think.teaching.mapper;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.think.teaching.model.ExpRate;

@Mapper
public interface ExpRateMapper extends BaseMapper<ExpRate> {
	
	@Select("SELECT AVG(rate) FROM exp_rate WHERE exp_id=#{expId}")
	Float getAvgRate(Integer expId);

}
